Author Question: What is meant by the cardinality of a relationship? What will be an ideal ... (Read 45 times)

ENagel · **on:** Jul 7, 2018

What is meant by the cardinality of a relationship?

What will be an ideal response?

Question 2

When creating SQL Server tables in a database, SQL statements can now also be submitted by using ________.

A) Internet Explorer
B) Microsoft PowerShell
C) Microsoft Excel
D) PL/SQL

elizabethrperez · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

In the E-R model, there are two types of cardinalitythe maximum cardinality and the minimum cardinality. The maximum cardinality is the maximum number of entity instances that can participate in a relationship instance. There are three types of maximum cardinality: one-to-one (1:1 ), one-to-many (1:N) and many-to-many (N:M). The minimum cardinality is the minimum number of entity instances that must participate in a relationship instance. This number is generally zero (0 ) or one (1 ). If the number is zero, then participation by that entity instance is optional (O)it does not have to be in a relationship with an instance of the other entity. If the number is one, then participation by that entity instance is mandatory (M)it must participate in a relationship with an instance of the other entity. In a binary relationship there are four (4 ) possible sets of minimum cardinalities(O-O), (O-M), (M-O) and (M-M).

Answer to Question 2

B